Characteristics Of Oil Samples Research Articles

Effects of magnetite and titania nanoparticles on properties of transformer insulating oil

Transformer oil-based nanofluids have become popular research topic due to their enhanced dielectric and thermal properties. Considering the sustainability aspects of extending the life of transformer oil, it is imperative to conduct research on the effect of transformer oil with nanofillers. In the present work, the influence of conducting magnetite (Fe3O4), semiconducting titania (TiO2) nanoparticles and combination of Fe3O4 and TiO2 nanoparticles (multi-nanoparticle) on AC breakdown voltage are investigated for various concentrations. Nanofluid prepared using multi-nanoparticle shows enhanced AC breakdown voltage (BDV) of transformer oil compared with unfilled oil. Enhancement in BDV of 22% is observed with combination of 0.0025 wt% Fe3O4 and 0.0075 wt% TiO2. In addition, the effect of titania nanoparticles dispersed into service-aged transformer oil with a weight percentage of 0.01% is investigated. Comparative study of breakdown strength and viscosity of nanofluid with unfilled oil is performed. Service-aged oil sample shows increased BDV of 15% with TiO2 nanoparticles. The degradation in service-aged transformer oil is analyzed using UV–vis and Fourier Transform Infrared (FTIR) spectroscopy. The characteristics of oil samples are analyzed using fluorescence spectroscopy.

Degradation and pollution of lands under the influence of oil resources exploitation

The research considers the degradation and pollution of soils as a result of oil extraction activities. The object of the research includes the territories of the exploited oil fields located in the Sarmatic mixed forests in Perm region. A total survey of the Gozhanskoye field was carried out, which revealed that the most dangerous processes of transformation and accumulation of pollutants are concentrated in the zone of influence of the primary oil treatment units (rus. UPPN, see the map). The other seven areas of the UPPNs were also surveyed. In total, 303 soil samples were taken as part of the study. The analysis determined such characteristics of oil samples as acidity, the content of humus, hydrocarbons, benzo[a]pyrene and chlorides. Measurements of oil content in the soil were carried out by the IR-spectrometry method. Benzo[a]pyrene was extracted from soil following the standard procedure and analyzed through gas chromatography testing. The physico-chemical analysis allowed to find out the concentrations of the main pollutants, as well as to design maps of land degradation and pollution. Another important finding is that the oil fields exploitation has the most essential impact on primary degradation of floodplain and upland soils as a result of salinization and benzo[a]pyrene pollution.

Unconventional vegetable oils as raw materials for biodiesel production

The aim of the study was to determine the possibility of using the unconventional vegetable oils for the biofuel production. The research material were cold-pressed oils from the seeds of milk thistle, hemp and evening primrose. After conducting the initial physicochemical characteristics of oil samples, including the determination of sulphur content, acid number, viscosity at 40°C, density at 15ºC, oxidation stability and fatty acid composition, analysed oils have been subjected to the transesterification process. The roduced methyl esters were further characterized by the above-mentioned features. Additionally, the temperatures of cold filter plugging point, cloud point and flash point were determined. On the basis of the conducted analyses it was demonstrated that the obtained oils, due to the high, far in excess of acceptable, values of the viscosity and density, and too low oxidative stability could not be used as a pure fuel. A similar conclusion was formulated in case of the produced methyl esters.

Geochemical Characteristics of Oil Samples from Tidal Zone and Shallow Water Area in Liaohe Depression

GC and GM-MS experiments are exerted for 34 oil samples in shallow water area of Liaohe Depression. The results show that Gas chromatograms are clear, continuous and intact which means the bio-degradation can be ignored. Originally the sediments are mainly deposited under oxidization environment. The oil resource is composed by the bacteria, aquatic organisms and higher plans. The depositional environment changes from reductive type to oxidization in the W-E direction. The salt content is high. From Lingnan well area in the west to Kuihua well area in the east the oil maturity increases. According to the depositional environment, source rocks and maturity features the oil samples are divided into 3 types. A is located in the west and centre of study area and Gammacerane index is less than 0.2. B in the centre and east. A and B are different in the organic import degree. To be specific the A is mainly supported by aquatic organisms while the B by continental materials. C has high gammacerane of more than 0.55, which comes from salt water environment.

Rheology of unstable mineral emulsions

In this paper, the rheology of mineral oils and their unstable water emulsion were investigated. The oil samples were domestic crude oil UA, its fractions UA1, UA4 and blend semi-product UP1, while the concentration of oil in water emulsions was in the range from 1 up to 30%. The results were analyzed based on shear stress. The oil samples UA, UA1 and UP1 are Newtonian fluids, while UA4 is pseudoplastic fluid. The samples UA and UA4 show higher value of shear stress (83.75 Pa, 297 Pa), then other two samples UA1 and UP1 (18.41 Pa, 17.52 Pa). Rheology of investigated oils due to its complex chemical composition should be analyzed as a simultaneous effect of all their components. Therefore, structural composition of the oils was determined, namely content of paraffins, naphthenes, aromatics and asphaltenes. All samples contain paraffins, naphthenes and aromatics but only oils UA and UA4 contain asphaltenes as well. All investigated emulsions except 30% EUA4 are Newtonian fluids. The EUA4 30% emulsion shows pseudoplastic behaviour, and it is the only 30% emulsion among investigated ones that achieves lower shear stress then its oil. The characteristics of oil samples that could have an influence on their properties and their emulsion rheology, were determined. These characteristics are: neutralization number, interfacial tension, dielectric constant, and emulsivity. Oil samples UA and UA4 have significantly higher values of neutralization number, dielectric constants, and emulsivity. The sample UA has the lowest value of interface tension and the greatest emulsivity, indicating that this oil, among all investigated, has the highest preference for building emulsion. This could be the reason why 20% and 30% emulsions of the oil UA achieve the highest shear stress among all investigated emulsions.

Effect of semiconductive nanoparticles on insulating performances of transformer oil

In this paper, TiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> semiconductive nanoparticles with a large relaxation time constant is added into transformer oil to form semiconductive nanofluids (SNFs), with the aim of enhancing insulating characteristics. ac, dc and lightning impulse breakdown voltage and partial discharge (PD) characteristics of oil samples before and after modification were measured according to ASTM standard methods. It was found that SNFs have ac, dc and lightning impulse breakdown voltage up to 1.2 times compared with pure oil. Meanwhile, the partial discharge resistance of SNFs was also dramatically improved. Charge trap and transportation characteristics of both samples have been measured by thermally stimulated current method (TSC) and pulse electroacoustic technique (PEA). It was found that electron shallow trap density and charge decay rate are greatly increased in semiconductive nanoparticles modified transformer oil. It is proposed that electron trapping and de-trapping processes in the shallow traps could be one of the main charge transport processes in dielectric liquids.